Push-pull cannulae were acutely positioned through previously implanted guides in the globus pallidus of unanesthetized freely moving cats and rats. During slow-flow perfusions, enkephalin release was detected in resting conditions and increased more than 3-fold when both 50 mM K+ and 1.8 mM Ca2+ were present in the perfusing medium. Local perfusion with veratrine also enhanced enkephalin release. Furthermore, in vivo, electrical stimulation of the rat caudo-putamen enhanced enkephalin release in the pallidum. This latter finding is consistent with a functional strio-pallidal enkephalin-containing pathway previously postulated by immunohistochemical or lesion experiments.

Animals↗

PubMed1980

Regional distribution of endorphin, Met5-enkephalin and Leu5-enkephalin in the pigeon brain.

The distribution of beta-endorphin and enkephalin in the pigeon forebrain by immunohistochemistry and radioimmunoassay is essentially analogous to mammals. Both endorphin- and enkephalin-reactive fibers have a similar periventricular distribution, but the enkephalin fibers are more extensive and are also found in the paleostriatum, limbic regions and brain stem, pituitary stalk and notably, penetrating the organum vasculosum hypothalami. There was poor correlation between endorphin and enkephalin regional contents by radioimmunoassay. In contrast, a highly significant correlation was observed between Met5-enkephalin and Leu5-enkephalin regional distribution. These data support the view that enkephalin neurons and endorphin neurons are independent central neuronal systems.

Animals↗

PubMed1978

Development of the aging cell surface: concanavalin A-mediated intercellular binding and the distribution of binding sites with progressive subcultivation of human embryo fibroblasts.

External surfaces of early and late passage human embryo fibroblasts were reacted with concanavalin A to determine whether quantitative and qualitative variations in receptor sites develop with increased serial subcultivation. Comparative analyses of direct con A binding to cell surfaces; lectin-mediated cell-to-cell binding and agglutination; and ultrastructural distribution of con A receptor sites were made on the surfaces of both cell groups. Subtle variations were observed in the patterns of intercellular binding between early and late passage cells as assayed by both agglutination and the binding of cells in suspension to substrate-attached monolayers. However, no major differences in the total number of binding sites per cell were expressed on the external surfaces of either group. Hemocyanin-labeled binding sites tended to be more clustered on membranes of late passage cells in contrast to more homogeneous patterns of distribution in early passage specimens. These observations suggest that variations in binding patterns are not the result of changes in numbers of binding sites but may be the result of alterations in the concerted actions of numerous factors which include cell surface topography (e.g. villous projections) and the relative distribution of lectin binding sites on the cell periphery.

Agglutination↗

PubMedDate not supplied

Elastic fibres in retinal detachment.

Generalised abnormalities have been described previously in familial and bilateral retinal detachment 1.2.3. Some studies have shown the presence of specific histological skin changes in cases of retinal detachment per se as well as in other syndromes having associated retinal detachment, hence pointing towards a generalised abnormality of constitution3.9.12. Drawing an analogy from these observations, the aim of our study was to study the histological changes in the skin of patients with rhegmatogenous retinal detachment and to relate its a etiopathogenesis to a generalized abnormality.

Adolescent↗

PubMedDate not supplied

Corneal thickness and I.O.P. changes in rhegmatogenous retinal detachment.

Twenty patients with Rhegmatogenous retinal detachment were subjected to applanation tonometry and Corneal Thickness measurement to ascertain (i) the change in central & peripheral corneal thickness and (ii) effect of Intra Ocular Pressure on these corneal changes. Twenty age and sex matched controls also underwent similar investigation. It was observed that both the mean Intra Ocular Pressure and the corneal thickness (both Peripheral Corneal Thickness and Central Corneal Thickness] of the affected eye showed statistically significant reduction (P 0.001) when compared to Intra Ocular Pressure and Corneal Thickness changes of fellow-eyes and eyes of control subjects. In addition to these even the fellow eyes which had normal Intra Ocular Pressure, showed statistically low Central Corneal Thickness measurement, when compared with controls. In view of the above observation and reduction in Corneal Thickness measurement, the present study indicates generalised corneal changes in Rhegmatogenous retinal detachment unrelated to intraocular pressure.

Cornea↗